DIY Class A/B Amp The "Wolverine" build thread

[poseidonsvoice]

Are any components included in the ground lift pcb from pcbway? I just noticed that the price for 5 pcs of the ground lift pcb is $37 and the price for 5 pcs of the T-ground pcb is only $6,50.

No, they are not. I ordered all the components for mounting these two pcb’s from Digikey. You do save when you buy and build in bulk not in singletons. You do have the option to use your own components from stock as well, the recommended components are just that, recommendations. But they are GREAT recommendations with regards to safety. The T-GND in particular is an excellent pcb. It makes the super crowded chassis ground bolt a much neater and safer feature imho.

Best,
Anand.

 

[poiy]

Are any components included in the ground lift pcb from pcbway? I just noticed that the price for 5 pcs of the ground lift pcb is $37 and the price for 5 pcs of the T-ground pcb is only $6,50.

I would give you the PCBs for free.
You would only have to pay shipping
PM me if you want

 

[danieljw]

No, they are not. I ordered all the components for mounting these two pcb’s from Digikey. You do save when you buy and build in bulk not in singletons. You do have the option to use your own components from stock as well, the recommended components are just that, recommendations. But they are GREAT recommendations with regards to safety. The T-GND in particular is an excellent pcb. It makes the super crowded chassis ground bolt a much neater and safer feature imho.

View attachment 1179570

Best,
Anand.

Hi Anand,

What is the single transistor in the left used for in this photo ?

- Dan

 

[poseidonsvoice]

@danieljw It's actually two transistors: An N-channel MOSFET (FQA40N25) sandwiched with a BD139 for thermal compensation. The N-channel is operated in source follower mode in a push pull design I had built recently. If you want more details, please pm me since I don't want to distract others (since this is the Wolverine build thread ) .

Best,
Anand.

 

[danieljw]

Fan sensor or Vbe multiplier ?

 

[poseidonsvoice]

Vbe multiplier.

Best,
Anand.

 

[danieljw]

Which amplifier design is that Anand?
Just out of curiosity

 

[Vunce]

Its this beauty!
page-70
Post# 1393

 

[wkloppen]

Thermal spreader improvements as suggested by fireanimal installed. See post links below.
Should I tap a hole between the 2 outputs or use the one just below the amp board which came with the modushop sink. I've understood mounting it directly ontop of the output is not the correct way. Too much thermal swings?...not a 100% sure....
#2057
#2065

 

[kokkie]

I am not an EE but I am familiar with thermal engineering. Temperature difference between the two points would be minimal and thermal delay is only a few seconds at the most. So it should not make a big difference. That said, I had the tools so I drilled a new hole between the 2 outputs.
The original hole for Q104 is a bit further away and with the increased thermal delay it probably would make a difference.

 

[fireanimal]

Thermal spreader improvements as suggested by fireanimal installed. See post links below.
Should I tap a hole between the 2 outputs or use the one just below the amp board which came with the modushop sink. I've understood mounting it directly ontop of the output is not the correct way. Too much thermal swings?...not a 100% sure....
#2057
#2065
View attachment 1180046

You can mount directly on the output transistor with no problem

 

[NSP]

I'm on my way to order parts from mouser, but the MBR1100G (D115, D116) is out of stock. They expect more next year.
Are there any replacement diodes for these?

 

[fireanimal]

I'm on my way to order parts from mouser, but the MBR1100G (D115, D116) is out of stock. They expect more next year.
Are there any replacement diodes for these?

There is stock at Newark https://canada.newark.com/on-semico...er-diode-single-100-v-1/dp/38K4498?CMP=AFC-OP

 

[NSP]

Strange, when I change country to Finland it says lead time is 51 weeks for the product. I'll se what I do.

This one seems to be in stock https://fi.farnell.com/en-FI/on-semiconductor/mbr1100g/schottky-rect-1a-100v-do-41/dp/2535567

 

[janusz]

Where are these D115 and 116 diodes? I do not see them in the parts list nor on the schematic. Did I miss something in this thread?
Thank you,

 

[janusz]

By the way, what about SB1100? It is also a schottky barrier rectifier 1A 100V. Mouser has a large stock of these.

 

[fireanimal]

Where are these D115 and 116 diodes? I do not see them in the parts list nor on the schematic. Did I miss something in this thread?
Thank you,

 

[janusz]

Thanks,
if these diodes are to replace these two resistors than SB1100 or SR3100 (3A 100v) should be good enough replacements, am I right?

 

[fireanimal]

hese diodes are to replace these two resistors than SB1100 or SR3100 (3A 100v) should be good enough replacements, am I right?

We are verifying

 

[janusz]

There are also SR1100 (1A) and SR2100 (2A) and the whole variety of SR diodes with higher and lower Voltages and Currents. SR1100 has junction capacitance of only 28pF so it's a very fast Schottky.